docs: def get_percent_identity(a_aln_seq, b_aln_seq):
      """Get the percent identity between two alignment strings"""
  
      if len(a_aln_seq) != len(b_aln_seq):
          raise ValueError('Sequence lengths not equal - was an alignment run?')
  
      count = 0
      gaps = 0
      for n in range(0, len(a_aln_seq)):
          if a_aln_seq[n] == b_aln_seq[n]:
              if a_aln_seq[n] != "-":
                  count += 1
              else:
                  gaps += 1
  
      return count / float((len(a_aln_seq) - gaps))